deskthority

Hi everyone,

Today I got a Datacomp DFK192 in what looks to be good condition. As it turns out, it appears to be dead. I have tried all 3 protocols (labelled with numbers) but am pretty sure the "30" marking is AT compatible (IBM model 30?) and this does not work.
What is happening:
-The keyboard is not registered on boot ("Keyboard not detected!")
-sometimes, the LEDs sporadically turn on and off (happened twice, sometimes the lights come on and stay on)
I have tried:
-Checking continuity on cable (good). I am pretty sure the cable is original and have confirmed it is wired correctly for the keyboard.
-Checking for shorts on the controller-side (good, I think - I did find one short but still have the same problem)
-Unplugging and plugging while on (works for my Monterey but not for this)
-Visually assessing the board (caps look fine but I cannot guarantee they are and will only replace them if it could be the cause)
-Connecting it to my XT-USB converter and changing protocols does nothing.
-Connecting to a different PC

The keyboard has possibly been repaired previously as some traces have been scraped between most likely to fix a poorly soldered joint. The oscillator looks somewhat out of place and looks to have been reflowed but it might be normal or maybe a replacement that isn't correct?. I can add some pictures if anyone thinks it could help.

I don't want to accept the fact that the board is dead because its so damn nice. Any help is greatly appreciated as always.

Thanks!

Swapped the electrolytic caps out and still the same result - it's not looking too good for the keyboard at this point.

With some effort you could replace the controller with a Teensy++, but it would be USB-only from then on.

I think this might be the best solution if nothing else works. It's going to be hard to do though. I think I might try and replace the oscillator first but I can't find any references for what type to use as there is pretty much one picture showing the controller up close.

I've done some testing today with a DMM and discovered that all the pins on the ICs are grounded. Not sure if it's normal (pretty sure it's not) so I tested another keyboard (that works) and that isn't the case. In other words, I think the keyboard is pretty fucked.

Controller replacement then?

looks that way, when I get time I might trace out the matrix and see what I can do with it but that sadly won't be for a good while.